The field of Socially Intelligent Agents (SIA) is a fast growing and increasingly important area that comprises highly active research activities and strongly interdisciplinary approaches. Socially Intelligent Agents, edited by Kerstin Dautenhahn, Alan Bond, Lola Canamero and Bruce Edmonds, emerged from the AAAI Symposium "Socially Intelligent Agents -- The Human in the Loop". The book provides 32 chapters, written by leading SAI researchers, addressing topics such as: social robotics, embodied conversational agents, affective computing, anthropomorphism, narrative and story-telling, social aspects in multi-agent systems, new technologies for education and therapy, and more. This breadth of topics covered in Socially Intelligent Agents provides the reader with a comprehensive look at current research activities in the area. Socially Intelligent Agents serves as an excellent reference for a wide readership, e.g. computer scientists, roboticists, web programmers and designers, computer users, cognitive scientists, and other researchers interested in the study of how humans relate to computers and robots, and how these agents in return can relate to humans. This book is also suitable as research material in a variety of advanced level courses, including Applied Artificial Intelligence, Autonomous Agents, Human-Computer Interaction, Situated, Embodied AI.